Novel simple indirect control concepts for an active power filter (APF) application are proposed here. The concepts are exemplarily presented to control a modified APF structure. The main advantage ...over other control strategies is the achieved excellent simplicity-to-performance ratio. The proposed control strategies are based on the concept of virtual impedance emulation to provide high power factor in a system. To validate the operating principle, a single-phase low-power prototype has been built and experimentally tested. This prototype operates at a remarkably low switching frequency of 5 kHz and is digitally controlled by a digital signal processor.
This paper provides a systematic review of advanced control strategies for the two mostly acclaimed standalone/off-grid distributed generation (DG) systems, i.e., wind energy conversion systems ...(WECSs) and solar photovoltaic energy systems (PVESs). The existing literature individually studies each DG system and does not provide an appropriate categorization of available advanced control strategies. Thus, it is quite difficult to systematically comprehend the control requirements of overall standalone/off-grid DG systems. Unlike the existing literature, this paper conducts a systematic study based on a useful distinctive organization of the advanced control strategies for the standalone permanent magnet synchronous generator (PMSG)-/doubly-fed induction generator (DFIG)-based WECSs and PVESs. The generalized control configurations for both standalone/off-grid DG systems are specifically exhibited by assigning a control system (CS) with its inherent inputs and outputs for every power conditioning unit (PCU) in the corresponding generation system. The advanced control techniques for all CSs are distinctively classified based on the presented generalized control configurations for both DG systems. Then, a comprehensive review is performed on every control technique with regard to its control functionality in the particular CS. Last, significant future research recommendations are provided for both standalone DG systems keeping in view the improved control strategies and PCUs.
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•A systematic review of the advanced control strategies is presented for the standalone/off-grid wind and solar photovoltaic (PV) energy systems.•The generalized control configurations for both systems are presented distinctively in the form of control systems (CSs).•Based on the specified CSs, the control strategies for each energy system are uniquely classified and then comprehensively studied considering the essential control operation of each CS.•The appropriate numerical data analysis, tables and graphical results are presented to properly understand the pros and cons of every advanced control strategy.•The useful future research recommendations are provided to achieve the improved control strategies and hardware components for the wind and solar PV energy systems.
Problem. As one of the three key elements of flexible manufacturing systems (FMS), automated guided vehicles (AGVs) play a significant role in material handling systems. They've been around for more ...than a decade, primarily in Europe. AGVs were formerly utilized mostly in production lines, but due to recent industrial development, they now play a vital role in a variety of different applications and domains, including warehouses, port facilities, transportation systems, and even the medical sector. Goal. The purpose of the work is to analyze two methods of AGV control and the paths that the AGV should follow during transport operations, taking into account safety and limitations for heavy loads that need to be transported in difficult conditions. Methodology. We attempted to provide a summary of the two existing AGV control methods, centralized and decentralized control offered by major manufacturers in this study. Almost all function in a centralized manner, with a single central controller controlling the whole fleet of AGVs. The author sees a tendency toward decentralized systems in which AGVs make individual decisions in favor of transportation flexibility, robustness, and adaptability. A brief explanation of well-known and mature navigation technologies used by AGVs in the industry is also provided, along with both physical and virtual paths to be followed by the AGV during transportation operations, since these technologies get to be a key issue given the safety constraints, particularly for heavy loads to be transported in challenging environments. Results. This paper covers one of the key tasks that must be completed in order to control an AGV system for a central and decentral architecture, for which we have already given a broad overview, as well as the differences between the architectures and their benefits and drawbacks. Originality. The author sees that the merging of various techniques we have will lead to more and new challenges as well as innovations, however, that practical application of distributed control still requires further research and studies and has a way to go in terms of taking other sections such as safety and sustainability into account. Practical value. The primary benefits and drawbacks of various technologies are discussed, as well as how we might improve the efficiency of some of them.
There are many different derivatives of the variable and fixed frequency switching control techniques used in the control of load resonant converters. In this study; among these techniques frequency ...modulation (FM), phase shift modulation (PSM) and pulse density modulation (PDM) are applied separately to series resonant converter (SRC). The techniques are examined and compared in many respects. An experimental setup was built, which consists of a 400W converter (with the input voltage of 200 V and the output voltage of 36V), a control circuit and a resistive load to verify the theoretical studies. The converter is controlled by FM, PSM and PDM separately for 120 kHz basic operating frequency and different output currents. The experimental results are compared in terms of efficiency, output voltage ripple, soft switching, switch voltage and ease of application and hardware. The comparison results are presented. It is observed that FM has better performance than the other two techniques in many aspects.
Electric vehicles (EVs) are playing a vital role in sustainable transportation. It is estimated that by 2030, Battery EVs will become mainstream for passenger car transportation. Even though EVs are ...gaining interest in sustainable transportation, the future of EV power transmission is facing vital concerns and open research challenges. Considering the case of torque ripple mitigation and improved reliability control techniques in motors, many motor drive control algorithms fail to provide efficient control. To efficiently address this issue, control techniques such as Field Orientation Control (FOC), Direct Torque Control (DTC), Model Predictive Control (MPC), Sliding Mode Control (SMC), and Intelligent Control (IC) techniques are used in the motor drive control algorithms. This literature survey exclusively compares the various advanced control techniques for conventionally used EV motors such as Permanent Magnet Synchronous Motor (PMSM), Brushless Direct Current Motor (BLDC), Switched Reluctance Motor (SRM), and Induction Motors (IM). Furthermore, this paper discusses the EV-motors history, types of EV-motors, EV-motor drives mathematical modelling, and design procedure of EV-motors. The hardware results have also been compared with different control techniques for BLDC hub and SRM. Future direction towards the design of EVs by a critical selection of motors and their control techniques to minimize the torque ripple and other research opportunities to enhance the performance of EVs are also presented.
This paper investigates the performance of an integrated control system based on the acoustic black hole effect and piezoelectric actuators for structural vibration suppression in beams. The acoustic ...black hole is a technique for passive vibration control consisting of a power-law tapered profile built on structures. Its effect takes place in the acoustic black hole termination, where the velocity of the incoming wave is reduced to zero so that the wave never reaches the tip of the wedge, and therefore the vibration energy is concentrated within the acoustic black hole. Here, we consider embedded and equally spaced elliptical-shaped acoustic black holes. The active control, in turn, consists of piezoelectric actuators which are operated by a linear quadratic regulator scheme in order to improve the control performance. We use the finite element method to discretize the structural domain, the modal analysis to obtain the vibration modes, and the fast Fourier transformation for calculating the maximum amplitudes of vibration in the frequency domain. All numerical tests are performed in a two-dimensional cantilever beam under free vibration conditions in order to evaluate the efficiency of the passive and active control techniques proposed in this work.
•Vibration analysis of a control system with acoustic black hole-type structures.•Finite element-based approach for structures equipped with acoustic black holes.•Control systems with acoustic black holes and piezoelectric actuators.•Acoustic black hole characterization with active control via piezoelectric actuators.
•Passive cases with strategies of solar control reduced insolation and energy demands.•A simple design with mixed strategies saved 76.57% while a complex design alone 66%.•The most suggested ...solutions are complex FSS and SDs but well-oriented and designed.•Optimal azimuth angle is crucial indicator for planning strategic designs placement.•Complex designs can be used for the integration of renewable solar cooling system.
Urban patterns without highly designed buildings increase the urban heat and energy demands. Solar control techniques encompass strategies that, if properly designed and applied, can decrease solar radiation and cooling demands. The aim of this research is to establish and recommend the most effective and balanced solutions to decrease insolation and increase energy savings while balancing daylighting and visibility. Four main classes were reviewed: façade self-shading, shading devices, window-to-wall-ratio and building orientation. The results showed that the cases with such passive strategies effectively lowered the insolation and achieved potential energy savings of 4.64% to 76.57%. The strategies selected for six cases were suitable for subtropical and temperate zones. The most recommended solutions were complex designs of façade self-shadings and shading devices; their strategic placements and accurate designs can further improve their performance. The optimal building orientation is essential for determining optimal façades for the strategic placement of both complex and simple designs. A worldwide guide of azimuth angles was calculated for 59 locations. The results show that 58.62% locations should apply complex designs to the east, 24.13% to the northeast, 12.06% to the west and 5.17% to the southeast orientations for solar protection. In tropical and subtropical zones, complex designs can be integrated with renewable technologies.
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